Most of the technology in Chilling Adventures of Sabrina suggests some time before the 1990s but after the 1940s. Cellphones, so ubiquitous in the modern world since at least 2005, are conspicuous in their absence. Every phone call is made with a landline (or occasionally through magic). If there are any personal computers, even, they do not seem to play an important role. The cars mostly seem to be much older models, and several people—especially Sabrina—have hairstyles that seem to evoke an earlier era. Some of the cultural references are relatively dated, too: the characters talk a lot about Alien, The Rocky Horror Picture Show, or even "16 Going On 17", but I do not recall any references to Justin Bieber or the Spice Girls, or indeed, anything after 1990.
On the other hand, in terms of vocabulary and mannerisms, the human characters certainly talk more like teenagers from 2010 than like teenagers from the 80s, let alone earlier. Further, in terms of the culture of the school body and administration, the school often seems more characteristic of a modern educational institution than what one would likely encounter in a small town in some 30 or more years back. For instance, when Nick goes to the school, he joins the school LBGTQ Alliance; while the Gay Activists Alliance, probably the inspiration for most of these groups, was founded in 1969, it would have been rather unlikely to find an analogous high school club, let alone in a small town. Also, for what it is worth, in the alternate universe, Harvey (or his actor?) talks about #Habrina, with Twitter of course having popularized hashtags.
So in what time period does Chilling Adventures of Sabrina take place? Or does it not take place in any particular year?